Final answer:
In a solo sonata with a single melody instrument and basso continuo accompaniment, usually two musicians are required.
Step-by-step explanation:
In a solo sonata featuring a single melody instrument and basso continuo accompaniment, typically two musicians are required.
The melody instrument, such as a violin or flute, plays the main melody, while the basso continuo, usually played by a bass instrument such as a cello or double bass, provides the harmonic foundation. The two musicians work together to create a balanced and harmonious performance.